LGC, Fordham, Cambridgeshire, UK; Drug Control Centre, Department of Analytical, Environmental and Forensic Sciences, King's College London, UK.
Drug Control Centre, Department of Analytical, Environmental and Forensic Sciences, King's College London, UK.
Steroids. 2019 Jun;146:79-91. doi: 10.1016/j.steroids.2019.03.011. Epub 2019 Apr 2.
Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. Urine from the uncastrated male horse contains boldenone that is thought to be of endogenous origin and thus a threshold ('cut-off') concentration has been adopted internationally for free and conjugated boldenone to help distinguish cases of doping from its natural production. The testis is likely to be a source of boldenone. Qualitative analysis was performed on extracts of equine testicular homogenates (n = 3 horses) incubated non-spiked and in the presence of its potential precursors using liquid chromatography tandem mass spectrometry (LC-MS/MS) and LC high resolution mass spectrometry (LC-HRMS). Samples were analysed both underivatised and derivatised to increase the certainty of identification. In addition to previously reported endogenous steroids, analysis of non-spiked testicular tissue samples demonstrated the presence of boldenone and boldienone at trace levels in the equine testis. Incubation of homogenates with deuterium or carbon isotope labelled testosterone and androstenedione resulted in the matching stable isotope analogues of boldenone and boldienone being formed. Additionally, deuterium and carbon labelled 2-hydroxyandrostenedione was detected, raising the possibility that this steroid is a biosynthetic intermediate. In conclusion, boldenone and boldienone are naturally present in the equine testis, with the biosynthesis of these steroids arising from the conversion of testosterone and androstenedione. However, additional work employing larger numbers of animals, further enzyme kinetic experiments and pure reference standards for 2-OH androstenedione isomers would be required to better characterize the pathways involved in these transformations.
宝丹酮是一种合成代谢雄激素类固醇，在赛马运动中被禁用。未经去势的公马尿液中含有宝丹酮，据认为其来源于内源性，因此国际上采用了一个（“cut-off”）阈值浓度，以帮助区分兴奋剂和其天然产物。睾丸可能是宝丹酮的来源之一。对未加标和加标潜在前体的马睾丸匀浆提取物（n=3 匹马）进行了液相色谱串联质谱（LC-MS/MS）和 LC 高分辨质谱（LC-HRMS）的定性分析。为了提高鉴定的确定性，对未衍生和衍生的样品进行了分析。除了先前报道的内源性甾体外，对未经加标睾丸组织样本的分析表明，宝丹酮和 Boldienone 以痕量水平存在于马睾丸中。用氘或碳同位素标记的睾酮和雄烯二酮孵育匀浆后，形成了宝丹酮和 Boldienone 的匹配稳定同位素类似物。此外，还检测到氘和碳标记的 2-羟基雄烯二酮，这增加了这种甾体可能是生物合成中间体的可能性。总之，宝丹酮和 Boldienone 天然存在于马睾丸中，这些甾体的生物合成来源于睾酮和雄烯二酮的转化。然而，需要更多的动物、进一步的酶动力学实验以及 2-OH 雄烯二酮异构体的纯参考标准，以更好地描述这些转化涉及的途径。
